Vehicles can become electrically charged as they are driven. To avoid discharge processes, provision must be made for adequate dissipation of the electrostatic charges. In order to be able to dissipate the electrostatic charge, tire components are made electrically conductive, presenting an electrically conductive path from the contact surface of the pneumatic vehicle tire with the roadway to the contact region of the pneumatic vehicle tire with the tire rim. This can be accomplished through the use of electrically conductive rubber mixtures, for example.
Development is now moving toward reducing the rolling resistance of the tire. One approach to reducing rolling resistance is to use rubber mixtures with a low rolling resistance. The hysteresis of these rubber mixtures with a low rolling resistance can be reduced above all by the use of low-activity fillers, smaller quantities of filler or by the replacement of carbon black by silica. However, the use of these rubber mixtures with a low rolling resistance leads to an increase in the electrical resistance of these rubber mixtures, with the result that the electrical conductivity falls. The required electrical resistance of the overall tire of at most 1×108 Ω to enable the electrostatic charge to be dissipated cannot be ensured.
An electrically conductive material is intended to mean a material, the electrical conductivity of which is such that the tire has an electrical resistance of at most 1×108 Ω. An electrically nonconductive rubber mixture is intended to mean a rubber mixture with which the tire has an electrical resistance greater than 1×108 Ω.
What are referred to as conductive carbon blacks in very small concentrations are often used as a remedy. However, these have a reinforcing/stiffening effect and also have a negative effect on hysteresis behavior and thus on rolling resistance. Moreover, such a measure based on conductive carbon blacks is expensive. Thus development is moving toward reducing the use of electrically conductive rubber mixture in the pneumatic vehicle tire.
United States patent application publication 2013/0174951 discloses a pneumatic vehicle tire having a carcass, wherein elements in the form of threads which are of electrically conductive configuration are arranged on at least one of the two surfaces of the carcass, thereby improving the electrical conductivity of the pneumatic vehicle tire. To achieve this, after the production of the carcass component in a calender, the elements in the form of threads are applied to at least one surface of the carcass. The problem here is that the carcass is exposed to severe stresses during tire production. If, for example, the elements in the form of threads do not have sufficient stretch, reliable dissipation of the electrostatic charge is not guaranteed since the elements in the form of threads tear and the electrically conductive path is interrupted. When using materials other than rubber in the pneumatic vehicle tire, provision must furthermore be made to ensure connection to the rubber matrix. Additional preparation steps are often necessary for this purpose. This increases the expense and complexity of the production process.